The present invention relates to a clamp for gripping receptacles each having a neck provided with a projecting collar. Devices of this type are suitable for use, for example, in receptacle transporters such as transporter stars of the kind used in particular in installations for filling such receptacles.
A star is generally constituted by a rotary platform having a peripheral portion in which notches or slots are formed. Each notch opens out laterally to receive a portion of the neck in such a manner that the collar rests on a portion of the top surface of the platform adjacent to the edge of the notch. The necks are held in the notches by a rail which extends around the platform so as to prevent the necks from leaving the notches. Nevertheless, there is a risk of a receptacle becoming wedged between the rail and the platform, giving rise to jamming. The rail then needs to be dismantled in order to enable the wedged receptacles to be removed. Such action is relatively lengthy and requires the installation to be stopped beforehand. In addition, a further drawback of such stars lies in the fact that at high rates of throughput the amount of centrifugal force acting on the receptacles tends to cause them to tilt and thus runs the risk of causing accidents, such as the jamming as described above, while receptacles are being transferred from one star to another.
In another type of transporter star, the rotary platform is fitted at its periphery with clamps each comprising two jaws which are connected to each other by a hinge pin extending parallel to the axis of rotation of the platform, and which are arranged to take hold of the receptacle via its neck, either above or below the collar. That solution avoids the above-mentioned drawbacks but is complex and relatively expensive.
An object of the invention is to make it possible in simple and relatively inexpensive manner to grip receptacles each comprising a body and a neck having a projecting collar presenting a bearing face that extends substantially radially on its face looking towards the body.
According to the invention, this object is achieved by a clamp for gripping such receptacles, the clamp comprising first and second jaws, the first jaw being arranged to co-operate with the bearing face of the collar and the second jaw being arranged to co-operate with a zone of the neck that extends adjacent to the bearing face, and on the side thereof that is remote from the body when the clamp is in its closed, gripping position.
The receptacle is thus held by the first jaw acting on the bearing face of the collar and the second jaw acting on the portion of the neck that is above the bearing face. The clamp can be simple in structure, and when the gripping clamp is mounted on a platform, there is no need to make use of an outer rail for holding the receptacles on the platform. In addition, with this structure receptacles can be transferred simply between two platforms.
Preferably, the first jaw comprises a collar abutment secured to a structural member, and the second jaw comprises a holding element mounted to move relative to the structural member to exert pressure on said zone of the neck in such a manner as to hold the collar in position against the abutment.
Advantageously, the clamp includes a support member having a substantially horizontal face forming the abutment, the support member preferably having a laterally open notch for receiving a portion of the neck adjacent to the collar.
The abutment then presents a relatively large area for co-operating with the bearing face of the collar, and the edge of the notch can also serve to position the neck laterally.
In a particular embodiment, the holding element is mounted relative to the support member to pivot about a hinge pin which is substantially perpendicular to the face of the abutment and has an end adjacent to the notch to bear laterally against the collar in such a manner as to hold the neck in the notch.
The holding element then serves to hold the neck in the notch, and the bearing face of the collar against the abutment face without occupying the zone that extends above the collar. This structure is particularly advantageous for use on a platform for screwing on screw caps, since the gripping clamp can then be arranged in such a manner as to avoid interfering with the movements of the screw-tightening shank. In addition, since the dimensions of the collar are common for a variety of receptacle sizes, holding by means of the collar present the advantage of enabling receptacles of different sizes to be gripped without modifying the clamp.
Advantageously, the holding element has at least one tooth arranged to bite into the collar.
The holding element thus ensures that the collar is gripped firmly.
According to another advantageous characteristic, the clamp has a member for bearing laterally against a portion of the neck, which bearing member is spaced apart from the abutment.